Objective:To investigate the epidemiological characteristics of newly diagnosed childhood leukemia in Children’s Hospital of Chongqing Medical University between 2000 and 2009

and to understand the features of childhood leukemia in the region of Chongqing

so as to provide references for prevention of childhood leukemia.Methods:The records of 915 children with leukemia who were initially diagnosed at Children’s Hospital of Chongqing Medical University from January 2000 to December 2009 were retrospectively studied.Results:The number of cases increased from 26 up to 156 in this decade

with annual increase of 19.6%.Of the 915 patients

71.48% were diagnosed as Acute lymphoblastic leukemia(ALL)

among whom

382 children were classified as B-cell ALL.47.59% patients had clonal abnormalities.The ratio of males to females was 1.63:1.Most of the patients were younger than 10 years(80.55%).ALL was most common in 1～4 years age group.Conclusions:The newly diagnosed childhood leukemia has continuously upward trend in Children’s Hospital of Chongqing Medical University.There are differences in the epidemiological characteristics of childhood leukemia between Chongqing and other regions

which suggests that there might be differences in the pathogenesis of childhood leukemia in different ethic origins and different environmental exposures.